ARCHIVED - Research About - Infectious Diseases

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The Canadian Institutes of Health Research (CIHR) is the Government of Canada's agency for health research. CIHR's mission is to create new scientific knowledge and to catalyze its translation into improved health, more effective health services and products, and a strengthened Canadian health-care system. Composed of 13 Institutes, CIHR provides leadership and support to more than 13,000 health researchers and trainees across Canada. Through CIHR, the Government of Canada invested approximately $ 263.5 million in 2008-09 in infectious diseases-related research.

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The Facts

• Data collected in 2007 indicated that 64.1% of seniors reported having received a flu shot during the 12 months before they were surveyed – a decrease from 66.2% in 2005.*
• Around the world, measles is a leading cause of death among young children, even though a safe and cost-effective vaccine is available to prevent the disease. In 2007, there were 197,000 measles deaths globally – almost 540 deaths every day.**
• More Canadians are living with HIV infection: an estimated 58,000 at the end of 2005 compared with 50,000 at the end of 2002.***
• Tuberculosis (TB) infection can become TB disease if the infected person's immune system cannot stop the TB bacteria from growing. A person who has TB infection and HIV or AIDS is 50-170 times more likely to develop TB disease than someone who does not have HIV.****

Sources:
* Health Canada, Healthy Canadians: A Federal Report on Comparable Health Indicators ; 
** World Health Organization, Measles;
*** Public Health Agency of Canada, HIV/AIDS Epi Updates November 2007;
**** Health Canada, Healthy Living, Tuberculosis, It's Your Health.

Finding Solutions

Why superbugs sometimes stay silent

Dr. Joaquin Madrenas and his colleagues at the University of Western Ontario's Robarts Research Institute have uncovered processes through which the often lethal effects of superbugs are kept in check. Staphylococcus aureus is the number one cause of hospital infections. The superbug's most deadly weapons are super antigens capable of triggering a massive immune system response that leads to Toxic Shock Syndrome, a rapid-onset, often deadly condition. Scientists have been trying to discover why individuals can carry the toxin-producing staph bacteria without getting sick. Dr. Madrenas' study, funded by CIHR and published in Nature Medicine in June, shows that molecules in the cell walls of staph adhere to receptors on the host's immune cells and spark production of a protein called interleukin-10 that helps neutralize antigen-presenting cells, allowing co-existence.

A new way to fight herpes virus

Scientists have discovered a new way for our immune system to combat the elusive virus responsible for cold sores: Type 1 herpes simplex virus (HSV-1). As reported in an online edition of Nature Immunology, a group of virologists from the University of Montreal, in collaboration with colleagues in the United States, have identified a cellular process that seeks out and fights herpes. The research team now plans to study how activation of the herpes-combating cellular process could be applied to other illnesses. The outcome could hasten the development of therapies to fight other immune-evading bacteria, parasites and viruses. "Our goal is to further study the molecules implicated in this mechanism to eventually develop therapies against diseases such as HIV or even cancer," says the study's lead author Luc English, a doctoral student under the supervision of Dr. Michel Desjardins.

Mining for new antibiotics

As more bacteria become resistant to antibiotics, the push is on to identify new bacteria-killing drugs or modify old drugs so that they are useful again. Dr. Gerard Wright of McMaster University in Hamilton heads up a CIHR-funded investigation of the molecular mechanisms of antibiotic resistance. In a study published in Animal Health Research Review in December 2008, he reports that advances in technology have aided in the discovery of novel antibacterial agents, especially through high-throughput screening – a robotics process that can quickly assess the potential of thousands, even millions, of chemical compounds – and genome mining for novel biosynthetic gene clusters.

The Researchers

Dr. Brett Finlay – The Guts of Asthma

A root cause of the asthma that has millions of Canadians wheezing, coughing and reaching for their inhalers might not be in our lungs, but in our guts. That's the intriguing working hypothesis of Dr. Brett Finlay, a University of British Columbia microbiologist.

His CIHR-funded research is at the forefront of a booming field exploring the links between the state of our gastrointestinal microbes and a previously unimaginable range of health issues, from obesity to childhood brain development.

"There is tantalizing and increasing evidence that changes in the gastrointestinal microbiota may also contribute to asthma," Dr. Finlay says.

The evidence trail begins with the fact that in the past decade in developed countries, including Canada, there's been an explosion in the number of children with asthma. Notably, however, the incidence of asthma in developing countries hasn't changed at all.

This has led to the hygiene hypothesis - that children in developed countries are experiencing more immune-related problems because they're not exposed to as great a variety of microbes. Notably, children treated with antibiotics are at greater risk of developing asthma.

"What's becoming more and more apparent is that the normal gastrointestinal microbes play a key role in the development of the immune system," says Dr. Finlay. "But until now nobody's ever done the experiments to see whether or not this is true for asthma."

Dr. Finlay's lab is perfectly placed to pursue this mystery. Two years ago he published a seminal paper that demonstrated that the composition of existing normal gut flora plays a role in an individual's susceptibility to an infectious disease.

"We've now shown that you can treat animals with different antibiotics to shift their flora and we can profoundly influence the outcome of the disease they get," says Dr. Finlay, whose research is part of the broader CIHR co-funded Canadian Microbiome Initiative.

His lab group, which includes two dozen graduate-level and post-doctoral students, is now using various antibiotics to change the gut flora of mice with asthma and observe the impact this has on the disease.

The research includes a unique cross-disciplinary collaboration with UBC Drs. Kelly McNagny, an asthma specialist, and Bill Mohn, an environmental microbiologist. Dr. Mohn has developed sophisticated tools for analyzing microbial populations in soil and marine environments.

"He's pioneered technologies for characterizing microbial populations in the environment and in this case the gut is just another environment," says Dr. Finlay. "It's the first time this technology is being applied to humans and human health."

For More Information

CIHR's Institute of Infection and Immunity (CIHR-III) has identified five strategic research priorities for Canada: emerging infections and microbial resistance; HIV/AIDS; immunotherapy; pandemic influenza preparedness; and vaccines of the 21st century. To learn more about these priorities and other CIHR-III activities, please visit the Institute's website.

For more information, go to ARCHIVED - Your Health Research Dollars at Work.